So, this was just to cool to not share! Dark matter could make planets habitable. I saw the article from the NewScientist.com detailing the theoretical idea of two astrophysicists from Fermilab in Batavia, Illinois. The actual science paper can be found here, on astro-ph.
The basic idea is that dark matter could be collected inside of a free-floating planet, a planet that has lost the star which warms it. This dark matter would generate enough heat to maintain liquid water on the surfaces.
I wrote an article on dark matter a couple of weeks ago on what it is and some of it's properties. But one of the interesting things about dark matter particles is that they annihilate on contact with each other, spraying out energetic particles. So when they travel through something as dense as a planet, they eventually get trapped from losing so much energy and settle into the core. As more dark matter particles settle in, the eventually collide and annihilate.
This piece of physics is even suspected to happen inside our own Earth, but at most generating a couple megawatts (the Sun gives us 100 billion megawatts as contrast). There is very little dark matter in the Solar System because we orbit in a region of the galaxy with little dark matter. Some dark matter exists closer to center of the Milky Way because of gravitational attraction, but the majority resides in a massive halo around the galaxy that helps give it it's shape.
|Dark Matter Halo Around A Galaxy.|
The density of dark matter particles would have to be immense to provide what the paper suggests, the best places are within 30 light years of the galaxies core. A region that is suggested to have poor planet formation, but better then in the halo where there are no stars to speak of. But even if it did happen, detecting them would be neigh impossible. The core of the galaxy is about 26,000 light years from us, and detecting a planet there isn't possible with any telescopes. The next generation of telescopes are going to be pushing it just to try to discover planets around stars 100 light years away.
So, there is a small chance for this kind of planet to exist and have life on it. But there is an even smaller chance of ever finding it. It would make for a great science fiction story setting though. And in my mind right now, I am envisioning the search for this planet kind of like trying to find a unicorn. Not just any unicorn either, but that ultra-rare, one-of-a-kind black unicorn (since this involves dark matter).
|Thanks Google Image Search.|